Colored oxide film of aluminum



Patented Feb. 11, 1936 COLORED OXIDE FILM OF ALUMINIIM Walter Anderau, Basel, Switzerland, assignor to Society of Chemical Industry in Basic, Basel,

Switzerland No Drawing. Application February 8, 1934, Serial No. 710 376. In Switzerland February 16, 1933 8 Qlaims.

This invention relates to the dyeing of an oxide film of aluminium or an alloy thereof with an organic dyestuff containing a metal in complex combination.

The oxide film of aluminium or an alloy thereof may be obtained by electrolytic oxidation, such as in a bath containing sulfuric acid, oxalic acid, ammonium bicarbonate or chromic acid.

As dyestuiis containing a metal in complex combination there may be used the mono-metal compounds, for instance the chromium, copper, nickel, cobalt, titanium, vanadium, manganese or iron compound of monoor p'oly-azo-dyestufis; also the poly-metal compounds of these dyestuffs or the complex metal compounds of anthraquinone derivatives, triarylmethane dyestuffs, azines, thiazines or oxazines; also the complex metal compounds of natural organic dyestufis, I

such as those of young fustic, old rustic, Persian berries, turmeric, quacitron, ellagic acid, cochineal, logwood or catechin.

The oxide film of the aluminium or its alloy may be dyed in various manners; for example, the film may be treated with a solution of a dyestufi containing the metal in complex combination in water, alcohol, acetone, pyridine, an oil varnish, parafiin oil or a fat; such a solution may be sprayed on to the oxide film or painted on it; or the dyestuff containing the metal may be printed in the form of a paste on the oxide film. The dye-bath may be neutral and may contain additions such as Glaubers salt; or it may be acid, containing mineral acid or organic acid. The temperature of the dye-bath may vary within wide limits; for obtaining the best results, however, it is in many cases of advantage to suit the temperature of the dye-bath to the degree of hydration of the oxide film, in such a manner that films of a weaker degree of hydration are dyed at a higher temperature and films of a stronger degree of hydration at a lower temperature.

The invention comprises also the dyeing of the oxide film of aluminium or an alloy thereof simultaneously with the production of the film. This modification has the advantage that there is only one stage in the process.

Furthermore, the dyestufi containing the metal in complex combination may be produced in the dye-bath, still further simplifying the procedure. According to the present process there are obtained new compositions of matter consisting of oxide films of aluminium and organic dyestuffs containing complexly bound metal. These compositions of matter show very vivid tints which are very uniform and possess excellent iaetness properties.

The following examples illustrate the inventim. the parts being by weight:-

Example 1 10 parts of the chromiferous azo-dyestufl ob= tai'ned by chroming the azo-dyestufl of the formula I on I Y A dye-bath is prepared by dissolving the copper compound of the azo-dyestufi of the formula from diazotized 5-nitro-2-amlno-1-phenol and- 2-phenylamino-5-hydroxynaphthalene 7 sulphonic acid to the extent of 2-10 parts per litre of water, at 40 C.

By immersing the oxidized surface of aluminium in this bath there is obtained in a short time a strong blue-violet tint.

If instead of the copper compound, the corresponding chromium compound of this dyestufl is used, there is obtained a blue oxide film; the cobalt compound of the same dyestufi. dyes the film grey blue while the aluminium compound and also the nickel compound produces a blue violet.

Emmple 3 The dyestuif containing chromium and copper obtained from the disazo dyestuii of the formula no nos-- NH son: on

OaNH:

from 7 7' disulfo-5:5'-dihydroxy-2:2'-dinaphthylamine and 2 mol. of diazotized 2-amino-1-hydroxy-i-sulfaminobenzene in a bath of 2-10 per cent. strength at 60-65 C. colors an oxide film of aluminium very fast. strong blue-violet tints.

When the dyeing is conducted with the cupriferous azo-dyestuff obtained from the disazo-dyestun of the formula.

from 2 mol. diazotized i-hydroxy-2-amino-4-suifaminobenzene and 1 mol. of the product of the action of phosgene on z-amino-t's-hydroxynapthalene- 'l-sulfonic acid, there is obtained a blui'sh-.

red oxide film, whereas the cupriferous disazodyestufi' from 2 mol. diazotized 1-hydroxy-2- amino-4-sulfaminobenzene and 1 mol. 7:7'-disulfa-5 5'-dihydroxy-2 2'-dinaphthylamine dyes the oxide film of aluminium blue violet tints. Pure blue tints are obtained by using the cupriferous azc-dyestufi obtained from the disazo-dyestuff of the formula OH NH:

H NH:

from 1 mol. tetrazotized 4:4'-diamino-3:3-dicarboxydiphenyl and 2 mol. 1-amino-8-hydr0xynaphthalene-3 G-disulfonic acid.

Example 4 A dye-bath is prepared from 5 parts of the chromium compound of the sulfonated dyestufl of the formula HOOC CODE from 1 mol. 2:6-dichioro-benza1dehyde and 2 moi. ortho-cresotinic acid per litre of liquor. Aiready in the cold, and better at 50 C. this bath colors the immersed oxidized aluminium a vivid blue.

Reddish-blue tints are obtained by using the chromium compound of the dyestufi! Chromazurol S (Schultz, Farbstofitabellen, 5th edition, No. 554) and the chromium compound of Eriochrome Cyanine R (Schultz, Farbstoiftabellen, 5th edition, No. 553).

Example 5 To 1000 parts of an oxalic acid bath of 3 per cent. strength, which is to be used for producing an anodic film of aluminum (Zeltschrift fiir eiektr. Chemie, vol. 37, pages 721-724), there are OzNHI added 5 parts of the chromium compound of the azo-dyestuff of the formula from diazotized 4i-chloro-2-amino-i-phenol-6- .sulfonic acid and 1-phenyl-3-methyl-5-pyrazolone in aqueous solution. During the subsequent anodic treatment there is produced on pure aluminimum an oxide layer which is colored red.

Example 6 A dye-bath is prepared with 4 parts of the chromium compound from 1:2:4z5z6z8-hexahydroxyanthraquinone-3z'l-disulfonic acid of the formula on 0 on HO- SOIH H OH Example 7 superficially oxidized aluminium is immersed in an aqueous suspension of 10 percent. strength oi 1:2:5:B-tetrahydroxyanthraquirione ot the formula at 40. C. At the same time there is added an aqueous solution of copper sulphate and the liquid is boiled for 1 hour. At the end of this time the aluminium is colored stronguniform, very fast'violet tints.

Example s superficially oxidized aluminium is immersed at ordinary temperature in an alcoholioor acetonic solution of 0.5 per cent. strength of the nickeliferous dyestufi from the aao-estufi of the formula OH 0H from diazotized d-chloro-Z-amino-bphenol and A superficially oxidized aluminium is immersed for half-an-hour at 40-45 C. in an aqueous alcoholic or acetonic solution of 1-10 per cent. strength of the chromiierous and niclzeiiferous dyestufi obtained from the azo-dyestuff of the formula on on from diazotized *l-nitro 2 amino-l-phenol and resorcinol; the aluminium is colored a strong red. c

If the chromiferous azo-dyestufi from diazotized i-nitro-Z-amino-l-phenol-fi sulphonic acid and acetonacetic acid anilide or the cupriferous dyestuff from diazotized l-amino-Z-hydrcxynaphthalenei-sulfonic acid and l-hydroxynaphthalene, or the chromiferous azo-dyestuif from diazotized 4-nitro-2-amino-l-phenol 6 sulfonic acid and 2-hydroxynaphthalene, or the cobaltiferous dyestuff from diazotized -nitro-Z-amino- L-phenol and Z-aminonaphthalene, or the ferruginous dyestufi from dia'zotized 4-chloro-2- amino-l-phenol and Z-hydroxy-naphthalene is used in like manner for dyeing an oxide film of aluminium, the latter is dyed yellow, violet, brown or violet brown or black.

Example 10 2 parts oi. the cobalt compound of Gallocyanine DH made by heating Gallocyanine DH (Schultz, Farbstofftabellen, 5th edition, No. 626) with a cobaltous chloride solution are dissolved in water and an oxide film of aluminium is dyed with the solution at 60 C. Blue tints are obtained.

Blue tints are also produced by dyeing the oxide film of aluminium or an alloy thereof with Gallocyanine Blue G (Schultz, Farbstofltabellen,

5th edition, No. 637), in presence of sodium aluminate, that is to say with the complex aluminium compound of Gallccyanine Blue G.

Example 11 water and the solution is used for dyeing an oxide film of aluminium at a raised temperature; fast marine blue tints are obtained.

The copper compound obtained by treating Indochromine T with copper acetate dyes an oxide film on aluminium vivid blue tints.

Example 12 3 parts of logwood (Schultz, Farhstofitabellen, 5th edition, No. 938) are converted into the 00m plex iron compound by heating them in parts of water with 3 parts glycerine and 0.5 part of freshly precipitated ferric hydroxide.

An oxide film of aluminium dyed for til minutes in this solution is colored deep black.

Example 13 3 parts of old fustic extract (Schultz, rlostofitabellen, 5th edition, No. 925) are converted into the complex aluminium compound by boiling them for half-an-hour in 100 parts of water containing 2 parts of aluminium hydroxide. t yellow tints are obtained by dyeing an oxide film of aluminium or an alloy thereof with this solution.

What I claim is:--

1. Process of coloring an electrolytically=produced oxide film of aluminium or of an alloy thereof, consisting in treating the oxide film oi aluminium or of an alloy thereof with organic dyestuffs containing a metal in complex combt nation.

2. Process of coloring an electrolytically-produced oxide film of aluminium or of an alloy thereof, consisting in treating the oxide film of aluminium or of an alloy thereof with azo-dyastufis containing a, metal in complex combination.

3. Process of coloring an electrolytically produced oxide film of aluminium or of an alloy thereof, consisting in treating the oxide film of stuffs containing a metal in complex combination, which composition of matter shows very vivid tints which are very uniform and possess excellent fastness properties.

6. A new composition of matter consisting of two components, viz. an electrolytically-produced oxide film of aluminium and azo-dyestufis containing a metal in complex combination, which composition of matter shows very vivid tints which are very uniform and possess excellent fastness properties.

lent fastness properties.

8. A new composition of matter consisting of two components, viz. an eiectroiyticaiiy n-produc oxide iilm of aluminium and monoazo-dyestnita containing chromium in complex combination, which composition of matter shows very vivid tints which are very uniform and possess excei- 5 lent i'astness properties.

. WALTER ANDERAU. 

